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Mesoporous γ-AlOOH@Fe3O4 magnetic nanomicrospheres were synthesized using superparamagnetic Fe3O4 nanoparticles as the core and aluminum isopropoxide(AIP) as the aluminum source.The obtained magnetic nanomicrospheres were characterized by X-ray powder diffraction(XRD),transmission electron microscopy(TEM),scanning electron microscopy(SEM),N2 adsorption-desorption and vibrating sample magnetometry(VSM).The effects of preparation parameters such as hydrolysis time of AIP,concentration of AIP and coating layer number on microspheres were investigated.The results indicated that the mesoporous γ-AlOOH@Fe3O4 magnetic nanomicrospheres consisted of a mesoporous-AlOOH shell and a Fe3O4 magnetic core.The diameter of γ-AlOOH@Fe3O4 nanomicrospheres was about 200 nm,the thickness of mesoporous-AlOOH shell was about 5 nm and the average pore size was 3.8 nm.The thickness of the mesoporous-AlOOH shell could be controlled via layer-by-layer coating times.The formation mechanism of the mesoporous-AlOOH shell involved a “chemisorption-hydrolysis” process.
Mesoporous γ-AlOOH @ Fe3O4 magnetic nanomicrospheres were synthesized using superparamagnetic Fe3O4 nanoparticles as the core and aluminum isopropoxide (AIP) as the aluminum source. The resulting magnetic nanomicrospheres were characterized by X-ray powder diffraction (XRD) , scanning electron microscopy (SEM), N2 adsorption-desorption and vibrating sample magnetometry (VSM). The effects of preparation parameters such as hydrolysis time of AIP, concentration of AIP and coating layer number on microspheres were investigated. The results indicated that the mesoporous γ-AlOOH @ Fe3O4 magnetic nanomicrospheres consisted of a mesoporous-AlOOH shell and a Fe3O4 magnetic core. The diameter of γ-AlOOH @ Fe3O4 nanomicrospheres was about 200 nm, the thickness of mesoporous-AlOOH shell was about 5 nm and the average pore size was 3.8 nm. The thickness of the mesoporous-AlOOH shell could be controlled via layer-by-layer coating times. The formation mechanism of the mesoporous-Al OOH shell involved a “chemisorption-hydrolysis ” process.